Kiwi Plant Named &#39;RK 2018&#39;

ABSTRACT

A new and distinct kiwi plant of the species Actinidia chinensis is described. The cultivar results from a controlled pollination using a female A. chinensis selection RS1 and a male selection (Tomuri and Chieftain). Named parents (RS1, Tomuri and Chieftain) are believed to be unpatented cultivars in the United States. The new cultivar is distinguished by its medium fruit size, ovoid fruit shape, general hairlessness, greenish-brown fruit coloring, and its harvest date in mid-October in Italy.

Latin name: Actinidia Chinensis Planch.

Varietal denomination: Red Queen.

FIELD OF THE INVENTION

Genus and species of plant claimed: Actinidia Chinensis Planch.

PRIORITY CLAIM

The present application claims priority from Community Plant VarietyOffice (European Union) Application No. 20190516, filed Mar. 11, 2019,which is herein incorporated in its entirety by reference.

BACKGROUND OF THE INVENTION

Kiwi plants in cultivation are mainly varieties of A. deliciosa,although some A. chinensis and A. arguta varieties are grown. A.deliciosa and A. chinensis are closely related and varieties of bothtypes have large fruit (about 100 g) with hair on the skin. Mainvarieties of Kiwi plants include ‘Hayward’ (A. deliciosa) and ‘HORT16A’(A. chinensis). All Actinidia species are dioecious, so female varietieshave to be interplanted with male pollinizers to ensure fruitproduction. Fruit are usually cut and eaten with a spoon. Tomuri andChieftain are both esaploid males which are commonly used to pollinateesaploid varieties such as Hayward, and also RS1. As they are both notsynchronized with Red varieties, which bloom much earlier than Tomuriand Chieftain, so male pollen has to be collected from male vines oneyear in advance, and then distributed on females during blooming, eitherdry (mixed with lycopodium) or in a liquid solution.

RS1 is a red kiwifruit variety which germinates in Northern Italy around15 days before Hayward (means around 3^(rd) week of March) and blooms 15days before Hayward (means around April 20^(th)). It is a mediumvigorous plant with short interno-knots. It adapts to a wide range ofclimates, but barely stand temperatures below 0° C. cause of its highsensitiveness to Pseudomonas syringae pv.actinidiae (PSA), a bacteriathat can result in the death of kiwifruit vines. It is harvested inNorthern Italy about 35 days before Hayward, which means the last weekof September.

Fruits can be stored for 2-3 months at 0° C.

SUMMARY OF THE INVENTION

The present invention is a new and distinctive kiwifruit variety,designated RK 2018. It was obtained during the course of a planned plantbreeding program, which took place in the Emilia-Romagna region nearMilan, Italy between 2008-2013. The RK 2018 variety was selected from apopulation of seedlings obtained from freely-pollinated RS1 fruits.About 450 seedlings of RS1 fruits were pollinated with various males,particularly Tomuri and Chieftain, which both proved to be perfectlycompatible with RS1. RK 2018 first flowered in April 2011 and fruitswere assessed in October 2011. All referenced dates are northernhemisphere timings.

In 2012, RK 2018 variety was grafted on Hayward and Tomuri rootstock,and the asexually reproduced plants proved to be true to type.

In 2014, the first trial plot of plants grafted on both Hayward andTomuri were established in Latina, Italy. The resulting first fruitsharvested in 2016 proved to maintain the unique features observed in thenursery.

Germination period is 10-12 days before Hayward, which means about oneweek after RS1. Flowering period is last week of April, means 10 daysbefore Hayward and one week after RS1. Ripening period is last week ofOctober, about 25 days after RS1. Harvesting should be performed whenthe external pulp tends to lose its green color and starts to turn toyellow.

RK 2018 is moderately vigorous and has close internodes. The germinationpercentage during spring is very high: 70-85%. The plant has a bushygrowing habit and responds effectively to cuts of green pruning,generating a large number of offshoots. The RK 2018 variety presentspanicles with a number of flowers ranging from 2 to a maximum of 5. Theplant is malleable and responds very well to pruning. Production isuniform, with many single fruits, a few double fruits and a high shareof Category 1 fruits.

Fruits are oblong, of variable length between 50-80 mm and width between35-45 mm. The fruit's medial section is circular.

The peel has a green-brown shade of color and is glabrous. The pulp isyellow on the outside and red in the center. The red and yellow colorincreases in uniformity after the 4th year of implantation and so doesthe overall ripening of fruits. The fruit's columella is cream-white incolor and of a medium-soft consistency, more consistent in proximity ofthe stalk.

The shelf life of RK 2018 is strongly dependent on the harvestingmethod, but is typically 4-5 months and, in ideal conditions, it caneven reach 6 months.

Brix degrees at the time of consumption range from 18° to 24° with amedium level of acidity.

Distinctive characteristics of the variety include the following shownin Table 1:

Number Characteristics State-Expression  1 Plant: sex Feminine  2 Plant:parthenocarpy Absent  3 Plant: Vigour Medium  4 Young shoot: hairdensity Limited  5 Young shoot: anthocyanin Limited coloration on thegrowth edge  6 Stalk: thickness Medium  7 Stalk: offshoot color on theLight green sun-exposed side  8 Stalk: bark texture Slightly coarse  9Stalk: hair density Light 10 Stalk: lenticels size Small 11 Stalk:lenticels number Medium 12 Stalk: surface of the bud's base Medium 13Stalk: presence of pearls Absent 14 Stalk: size of the pearl's orificeAbsent 15 Leaf callus Concave 16 Stalk: fibrous part Fibrous, watery 17Leaf blade: shape Heart-shaped in the young age, more rounded in theadult age 18 Leaf blade: length/width ratio 1:1 19 Leaf blade: tip'sshape Lanceolate in the young age, rounded in the adult age 20 Leafblade: basal lobes Lightly overlapping 21 Leaf blade: number of ciliatedMedium indentations 22 Leaf blade: hair density in Absent the upper part23 Leaf blade: hair density in Very sparse-subtle the lower part 24 Leafblade: green intensity in Intense green the upper part 25 Leaf blade:color in the lower part Light green 26 Leaf blade: variegation Absent 27Leaf blade: variegation color Absent 28 Leaf: stalk length Long 29Stalk: anthocyanin color in Absent the upper part 30 Panicle: typeSingular 31 Panicle: number of flowers 4-7 32 Flower bud: first budposition Basal 33 Flower: number of sepals High 34 Flower: sepal maincolor Green 35 Flower: density of sepal hairs Medium 36 Flower: diameterMedium 37 Flower: petal placement Overlapping 38 Flower: profile shapeFlat 39 Flower: number of stigma Medium 40 Flower: placement of stigmaIrregular 41 Petal: main color of the White-yellowish adaxial side 42Petal: main color shade Regular 43 Petal: secondary color on Greenadaxial side 44 Petal: secondary color Almost absent distribution 45Anther: color Intense yellow 46 Fruit: weight Average weight: 85-90 gr47 Fruit: length 50-80 mm 48 Fruit: width 35-45 mm 49 Fruit:length-width ratio 1:1.7 50 Fruit: shape Ovoid 51 Fruit: shape incentral section Circular (approx. mid fruit) 52 Fruit: lower partLightly concave 53 Fruit: presence of sharp Absent protuberance 54Fruit: presence of ring at the calyx Absent 55 Fruit: edge shape at stemend Lightly rounded 56 Fruit: stem length Long 57 Fruit: stem length inrelation to Long fruit length 58 Fruit: presence of lenticels on skinLimited 59 Fruit: Absence of hair on skin Hairs sparsely present 60Fruit: hair density Very sparse 61 Fruit: hair color Light brown 62Fruit: hair adherence to skin Strong 63 Fruit: skin color Green-browndepending on light exposure 64 Fruit: hair adherence to pulp Strong 65Fruit: color of external pericarp Yellowish tending to green 66 Fruit:color of loculi-alveoli Red 67 Fruit: diffusion of red color around Highthe loculi-alveoli (if present) 68 Fruit: intensity of the red color inStrong the loculus 69 Fruit: extent of the columella in Medium relationto the fruit 70 Fruit: overall shape of the Circular columella in themid-section 71 Fruit: color of the columella Cream white 72 Fruit:sweetness High 73 Fruit: acidity Medium 74 Period of bud breakageMedium-premature 75 Period of flowering Averagely premature 76 Period ofripening for harvesting Averagely tardive

The new variety can be asexually reproduced, both by promoting roots oncuts, using warm beds, or more conveniently through grafting on selectedrootstocks. Plants grafted on male rootstocks proved to be more vigorousand more resistant than straight plants from cuts. Grafting can beoperated within a wide window, from May into July. English single ordouble cut is the most common grafting technique. Trial plantings ofgrafted plants established in both Emilia Romagna (Castelbolognese) andLatina area in 2014 have shown that the unique combination ofcharacteristics come true to form, are established, and transmittedthrough succeeding asexual propagations.

BRIEF DESCRIPTION OF THE DRAWINGS

Images show in the following identified pictures are from plants thatare approximately four years from grafting.

FIG. 1 shows typical fruit of the new variety in the orchard.

FIG. 2 shows closeup of typical fruit of the new variety in the orchard.

FIG. 3 shows typical fruit of the new variety in the orchard incross-section, 10 days before harvest.

FIG. 4 shows a typical fruit of the new variety in the studio and incross-section.

FIG. 5 shows a typical fruit of the new variety in the studio and on ascale.

FIG. 6 shows typical fruit of the parent female RS 1 species in thestudio, including in cross-section.

FIG. 7 shows typical fruit of the new variety in the studio comparedwith the parent female RS1 species, including in cross-section.

COMPARISON TO CLOSEST VARIETY

RK 2018 variety shows some distinctive features common to RS1 varieties,such as a navel at the bottom, a slightly pear shape, hairless fruitsand very high fertility.

Comparison with the similar variety RS1 (protected by CPVO Europe underthe title # EU46694) shows that RK 2018 may be distinguished as followsin Table 2:

Comparison With Similar Variety. Observations made under Italy GrowingConditions 2016-2019 Characteristic RS1 RK 2018 FRUIT: Harvest date LateSeptember Late October Color of ripe Bright yellow (44A)/ Greenishyellow (4B)/ pericarp* Bright red (44B) Bright red (44B) Skin colorGreenish brown Greenish brown (152D) (152D) Mean fresh weight 70-80grams 85-100 grams Mean dry matter at    19-23%    19-22% harvestAverage length 60 mm 70 mm Average width 37 mm 40 mm Core diameter 12 mm13 mm Width/length ratio 0.61 0.57 Sweetness (Brix at  20-22°  19-21°maturity for consumption) General shape Oblong Oblong Cross-sectionalshape Circular Circular Shape of stylar end Navel Navel Skin: HairnessAbsent Almost absent VINE: Shoots: Color 148A 148A Texture Smooth SmoothStem: Color (upper) 165A 166A Color (lower) 199A 199A Mean diameter 9 mm9.5 mm Texture Smooth Smooth Lenticels (if present) Present PresentLeaf: Color (upper) 134A 134A Color (lower) 134B 134C Shape OrbiculateOrbiculate Length 120 mm 130 mm Width 115 mm 120 mm Apex AcuminateAcuminate Base Cordate Cordate Margin Ciliate Ciliate Texture SmoothSmooth FLOWER: Inflorescence: Predominant number 5-6 4-7 of flowersPetiole: Length 100-105 mm 105-115 mm Color 162A 162B Pedicel Length 35mm 37 mm Color 135C 135C Hairs Smooth Smooth Length of hairs — — Flower:Coloration of petals Bi-colored Bi-colored Primary color 155A 155BSecondary color 145A 145B Base of petals 48 mm 50 mm diameterArrangement of Overlapping Overlapping petals Mean number of 5-6 6petals/flowers Mean length of petals 24 mm 26 mm Mean width of petals 21mm 22 mm Petal ratio of 1.15 1.17 length/width Petal shoulder PresentPresent Filament color 157A 157A Anthere color 6A 6B Attitude of stylesErect Erect Curvature of styles Absent Absent Color of styles 157A 157CAmount of hair on Dense Dense ovary Color of ovary 157A 157A Number ofsepals 6-7 6-7 Color of sepals 146C 146D Length of Sepals: Range8.5-11.0 mm 9.3-11.5 mm Mean length 10.0 mm 10.3 mm Sepals diameter 6.7mm 7.0 mm Flower opening Mid-April Late April Vegetative bud breakMid-March Late March Plant/fruit disease None None and pest resistancePlant hardiness zone Unknown Unknown or heat/cold resistance *RoyalHorticultural Society Color Chart 2001

The most striking differences between RS1 and RK 2018 are the fruitshape (RS1 is more pear-shaped, while RK 2018 is more cylindric shape)and size, flowering and harvest times, and storability. The fruit sizeis significantly bigger than RS1, and the biggest fruits on RK 2018 areobtained on medium wood, while the RSI needs larger, strong wood toreach decent size. The bud break and blooming of RK 2018 are bothdelayed by about 1 week beyond that of RS1. Also, fruit storability orRK 2018 is much longer than that of RS1, typically 4-5 months for RK2018 versus two months for RS1.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A new and distinct kiwiplant of the species A. Chinensis Planch substantially as hereindescribed and illustrated.